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Sample records for plenok diboridov tantala

  1. Niobia and tantala codoped orthorhombic zirconia ceramics

    International Nuclear Information System (INIS)

    Hoeftberger, M.; Gritzner, G.

    1995-01-01

    During recent studies it was found that codoping of zirconia with niobia and tantala yielded very corrosion resistant, orthorhombic zirconia ceramics. The powders for those novel ceramics were made via the sol-gel technique by hydrolysis of the respective metal propoxides; a method which required dry-box techniques during the preparation of the alkoxides. In these studies the authors investigated the fabrication of precursor material from aqueous solutions. The preparation of aqueous solutions of salts of zirconium, niobium and tantalum is hampered by rapid hydrolysis. Premature hydrolysis of the chlorides and oxichlorides of niobium, tantalum and zirconium can be, however, prevented in aqueous solutions of oxalic acid. Thus the authors investigated the coprecipitation of hydroxides as precursors by reacting oxalic acid solutions of the respective cations with aqueous ammonia. In addition they studied the effects of calcination and of hydrothermal conversion of the hydroxides to oxides on the powder characteristics and on the mechanical properties of the niobia and tantala codoped zirconia ceramics

  2. Investigations of the mechanical loss of tantala films between 5 and 300 K

    Energy Technology Data Exchange (ETDEWEB)

    Hudl, Matthias; Nawrodt, Ronny; Zimmer, Anja; Nietzsche, Sandor; Vodel, Wolfgang; Seidel, Paul [Friedrich Schiller University (Germany); Tuennermann, Andreas [Institute of Solid-State Physics, Helmholtzweg 5, D-07743 Jena (Germany),; Friedrich Schiller University-Institute of Applied Physics, Jena (Germany)

    2007-07-01

    Mechanical losses in dielectric mirror coatings of interferometric gravitational wave detectors are a main issue for the proposed advanced generation of gravitational wave detectors. Recent investigations have shown that the mechanical loss of the dielectric mirror coatings (tantala/silica stacks) is probably the main contribution to the detector noise. There are indications that among both coating materials tantala gives the major contribute to mechanical loss. Experimental details of a measuring setup and investigations of the temperature dependency of the mechanical dissipation in thin tantala films on different substrates are presented.

  3. Mechanical loss in tantala/silica dielectric mirror coatings

    International Nuclear Information System (INIS)

    Penn, Steven D; Sneddon, Peter H; Armandula, Helena; Betzwieser, Joseph C; Cagnoli, Gianpietro; Camp, Jordan; Crooks, D R M; Fejer, Martin M; Gretarsson, Andri M; Harry, Gregory M; Hough, Jim; Kittelberger, Scott E; Mortonson, Michael J; Route, Roger; Rowan, Sheila; Vassiliou, Christophoros C

    2003-01-01

    Current interferometric gravitational wave detectors use test masses with mirror coatings formed from multiple layers of dielectric materials, most commonly alternating layers of SiO 2 (silica) and Ta 2 O 5 (tantala). However, mechanical loss in the Ta 2 O 5 /SiO 2 coatings may limit the design sensitivity for advanced detectors. We have investigated sources of mechanical loss in the Ta 2 O 5 /SiO 2 coatings, including loss associated with the coating-substrate interface, with the coating-layer interfaces and with the coating materials. Our results indicate that the loss is associated with the coating materials and that the loss of Ta 2 O 5 is substantially larger than that of SiO 2

  4. Amorphous tantala and its relationship with the molten state

    Science.gov (United States)

    Alderman, O. L. G.; Benmore, C. J.; Neuefeind, J.; Coillet, E.; Mermet, A.; Martinez, V.; Tamalonis, A.; Weber, R.

    2018-04-01

    The structure factors of molten T a2O5 and N b2O5 have been measured by high-energy x-ray and pulsed neutron diffraction. These are compared to transmission-mode x-ray diffraction through a self-supported 15-μm ion-beam sputtered amorphous tantala film. Atomistic models derived from the diffraction data by means of empirical potential structure refinement reveal that tantala and niobia liquids are very close to isomorphous, as confirmed by measurement of a molten mixture, T a0.8N b1.2O5 . Nonetheless, peak Nb-O bond lengths are about 1 % shorter than those for Ta-O, at temperatures, T*=T /Tmelt , scaled to the melting points. Mean coordination numbers are nM O≃5.6 (1 ) ,nO M≃2.23 (4 ) in the liquid state, and nTaO≃6.6 (2 ) ,nOTa≃2.63 (8 ) in the solid. The liquids are built from five- and six-fold M -O polyhedra which connect principally by corner sharing, with a minority of edge sharing; a-T a2O5 on the other hand has a local structure more akin to the crystalline polymorphs, built primarily from six- and seven-fold polyhedra, with a larger degree of edge sharing. The structural differences between liquid and amorphous T a2O5 , coupled with observations of increasing peak bond lengths upon cooling, are consistent with the interpretation that the amorphous film reaches a supercooled liquidlike metastable equilibrium during deposition. In other words, the amorphous film shares a common progenitor state with a hypothetical glass quenched from a fragile melt. In addition, we show that recent classical interatomic potentials do not fully reproduce the diffraction data, and infer that inclusion of attractive (non-Coulombic) Ta-Ta interactions is important, particularly for obtaining the correct degree of edge sharing, coordination numbers, and densities. Nanoscale inhomogeneity of the amorphous film is confirmed by the observation of small-angle x-ray scattering.

  5. Effect of elevated substrate temperature deposition on the mechanical losses in tantala thin film coatings

    Science.gov (United States)

    Vajente, G.; Birney, R.; Ananyeva, A.; Angelova, S.; Asselin, R.; Baloukas, B.; Bassiri, R.; Billingsley, G.; Fejer, M. M.; Gibson, D.; Godbout, L. J.; Gustafson, E.; Heptonstall, A.; Hough, J.; MacFoy, S.; Markosyan, A.; Martin, I. W.; Martinu, L.; Murray, P. G.; Penn, S.; Roorda, S.; Rowan, S.; Schiettekatte, F.; Shink, R.; Torrie, C.; Vine, D.; Reid, S.; Adhikari, R. X.

    2018-04-01

    Brownian thermal noise in dielectric multilayer coatings limits the sensitivity of current and future interferometric gravitational wave detectors. In this work we explore the possibility of improving the mechanical losses of tantala, often used as the high refractive index material, by depositing it on a substrate held at elevated temperature. Promising results have been previously obtained with this technique when applied to amorphous silicon. We show that depositing tantala on a hot substrate reduced the mechanical losses of the as-deposited coating, but subsequent thermal treatments had a larger impact, as they reduced the losses to levels previously reported in the literature. We also show that the reduction in mechanical loss correlates with increased medium range order in the atomic structure of the coatings using x-ray diffraction and Raman spectroscopy. Finally, a discussion is included on our results, which shows that the elevated temperature deposition of pure tantala coatings does not appear to reduce mechanical loss in a similar way to that reported in the literature for amorphous silicon; and we suggest possible future research directions.

  6. Tantala-based sol-gel coating for capillary microextraction on-line coupled to high-performance liquid chromatography.

    Science.gov (United States)

    Tran, MinhPhuong; Turner, Erica B; Segro, Scott S; Fang, Li; Seyyal, Emre; Malik, Abdul

    2017-11-03

    A sol-gel organic-inorganic hybrid sorbent, consisting of chemically integrated tantalum (V) ethoxide (TaEO) and polypropylene glycol methacrylate (PPGM), was developed for capillary microextraction (CME). The sol-gel sorbent was synthesized within a fused silica capillary through hydrolytic polycondensation of TaEO and chemical incorporation of PPGM into the evolving sol-gel tantala network. A part of the organic-inorganic hybrid sol-gel network evolving in the vicinity of the capillary walls had favorable conditions to get chemically bonded to the silanol groups on the capillary surface forming a surface-bonded coating. The newly developed sol-gel sorbent was employed to isolate and enrich a variety of analytes from aqueous samples for on-line analysis by high-performance liquid chromatography (HPLC) equipped with a UV detector. CME was performed on aqueous samples containing trace concentrations of analytes representing polycyclic aromatic hydrocarbons, ketones, alcohols, amines, nucleosides, and nucleotides. This sol-gel hybrid coating provided efficient extraction with CME-HPLC detection limits ranging from 4.41pM to 28.19 pM. Due to direct chemical bonding between the sol-gel sorbent coating and the fused silica capillary inner surface, this sol-gel sorbent exhibited enhanced solvent stability. The sol-gel tantala-based sorbent also exhibited excellent pH stability over a wide pH range (pH 0-pH 14). Furthermore, it displayed great performance reproducibility in CME-HPLC providing run-to-run HPLC peak area relative standard deviation (RSD) values between 0.23% and 3.83%. The capillary-to-capillary RSD (n=3), characterizing capillary preparation method reproducibility, ranged from 0.24% to 4.11%. The results show great performance consistency and application potential for the sol-gel tantala-PPGM sorbent in various fields including biomedical, pharmaceutical, and environmental areas. Copyright © 2017 Elsevier B.V. All rights reserved.

  7. Preparation of Films and Sources for 4{pi} Counting; Prigotovlenie dlya 4{pi}-scheta plenok i istochnikov

    Energy Technology Data Exchange (ETDEWEB)

    Konstantinov, A. A.; Sazonova, T. E. [Vsesojuznyj Nauchno - Isledovatel' skij Institut Im. D.I. Mendeleeva, Leningrad, SSSR (Russian Federation)

    1967-03-15

    To obtain a high degree of accuracy in determining the specific activity of sources by the absolute counting of particles with a 4{pi} counter, attention must be paid to the preparation of the radioactive sources. At the Mendeleev Institute of Metrology, celluloid films (surface density 8-10 {mu}/cm{sup 2}) coated on both sides with gold (10-15 {mu}g/cm{sup 2} ) or palladium (5-6 {mu}g/cm{sup 2}) are used as the bases of the radioactive sources. In order to reduce the correction for absorption of beta particles in the radioactive deposit, the base is specially treated with insulin. The authors present an extremely sensitive and effective method, employing the electron-capture nuclide {sup 54}Mn ({sup 54}Cr), for determining the uniform distribution of the active layer over the entire insulintreated surface. A solution of {sup 54}Mn ({sup 54}Cr) salt was applied to the insulin-tteated film, and the source of {sup 54}Cr ({sup 54}Mn) Auger K electrons thus obtained was investigated with the help of a proportional 4{pi} counter. The total number of {sup 54}Cr ({sup 54}Mn) Auger K electrons from the source was 8-12% less than the fluorescence coefficient (calculated from the number of {sup 54}Cr ({sup 54}Mn) K X-quanta emitted by the source) and the number of K electrons absorbed in the film (determined by the 'sandwich' method). From the differences, for insulintreated and untreated {sup 54}Mn ({sup 54}Cr) sources, between the calculated and recorded number of Auger electrons it is possible to reach a definite conclusion regarding the quality of the insulin treatment. (author) [Russian] Dlja poluchenija vysokoj tochnosti izmerenij pri opredelenii udel'noj aktivnosti istochnikov metodom absoljutnogo scheta chastic s pomoshh'ju 4{pi}- schetchika, bol'shoe vnimanie dolzhno byt' udeleno prigotovleniju radioaktivnyh istochnikov. Vo VNIIM v kachestve podlozhek radioaktivnyh istochnikov ispol'zujutsja celluloidnye plenki (poverhnostnaja plot- nost' 8-10 mkg/sm{sup 2} ) , metallizirovannye s obeih storon zolotom (10 - 15 mkg/sm{sup 2}) ili palladiem (5 - 6 mkg/sm2 ) . Dlja umen'shenija popravki na pogloshhenie 8-chastic v sloe radioaktivnogo osadka primenjaetsja special'naja obrabotka podlozhki insulinom. Predlozhen ochen' chuvstvitel'nyj i jeffektivnyj metod dlja opredelenija ravno- mernosti nanesenija aktivnogo osadka po vsej obrabotannoj insulinom ploshhadi istoch- nika s ispol'zovaniem jelektronno-zahvatnogo nuklida marganec-54 (hrom-54). Na plenku, obrabotannuju insulinom, nanosilsja rastvor soli marganec-54 (hrom-54); poluchennyj istochnik K-jelektronov Ozhe hrom-54 (marganec-54) issledovalsja v proporcional'nom 4l- schetchike. Obshhee chislo K-jelektronov Ozhe hrom-54 (marganec-54), kotorye vyhodili iz istochnika, bylo men'she na 8-12% znachenija, rasschitannogo na osnovanii chisla KH-kvantov hroma-54 (marganec-54), ispuskaemyh istochnikom, kojef- ficienta fluorescencii i chisla K-jelektronov, pogloshhennyh v plenke, kotoroe oprede- ljalos' metodom {sup s}jendvicha{sup .} Ishodja iz raznostej mezhdu raschetnym i zaregistriro- vannym chislo'm jelektronov Ozhe dlja istochnikov marganec-54 (hrom-54), obrabotannyh in- sulinom i neobrabotannyh, mozhno odnoznachno sudit' o kachestve obrabotki insulinom istochnikov. (author)

  8. The effects of heating on mechanical loss in tantala/silica optical coatings

    International Nuclear Information System (INIS)

    Abernathy, Matthew R.; Harry, Gregory M.; Travasso, Flavio; Martin, Iain; Reid, Stuart; Rowan, Sheila; Hough, Jim; Fejer, Martin M.; Route, Roger; Penn, Steve; Armandula, Helena; Gretarsson, Andri

    2008-01-01

    Second-generation interferometric gravitational-wave detectors will operate at temperatures noticeably above room temperature. Study was done to determine what effect elevated temperatures would have on the Q and coating thermal noise of the detector mirrors. Results show that increased temperature increases loss angle in a manner that is more significant at higher frequencies. Trends show that the increased temperature will have a negligible effect at the low (100 Hz) frequencies important to second-generation detectors

  9. Structural influences on the laser damage resistance of optical oxide coatings for use at 1064 nm

    Energy Technology Data Exchange (ETDEWEB)

    Hacker, E; Lauth, H; Meyer, J; Weissbrodt, P [Zeiss Jena GmbH, Jena (Germany, F.R.); Wolf, R; Zscherpe, G [Ingenieurhochschule Mittweida (Germany, F.R.); Heyer, H [Sektion Physik, Friedrich-Schiller-Univ. Jena (Germany, F.R.)

    1990-11-01

    Optical coatings of titania (TiO{sub 2}) and tantala (Ta{sub 2}O{sub 5}) prepared by reactive r.f. diode and d.c. plasmatron sputtering were investigated for the influence of structural properties on the 1064 nm laser damage resistance. Using various methods of characterizing the compositional, crystallographic, microstructural and optical properties, it was found that the damage thresholds are directly related to the content of oxygen in the films in excess of the stoichiometric values, whereas grain sizes and refractive indices show no systematic influences valid for both oxide materials. The highest oxygen-to-metal atomic ratios and thus the highest damage threshold were achieved by the use of r.f diode sputtering. X-ray photospectroscopy investigations of tantala coatings with different oxygen-to-tantalum atomic ratios up to 2.75 revealed for both constituents of the oxide only binding energies representative for tantalum pentoxide. (orig.).

  10. Detection of negative ions in glow discharge mass spectrometry for analysis of solid specimens

    DEFF Research Database (Denmark)

    Canulescu, Stela; Molchan, Igor S.; Tauziede, C.

    2010-01-01

    A new method is presented for elemental and molecular analysis of halogen-containing samples by glow discharge time-of-flight mass spectrometry, consisting of detection of negative ions from a pulsed RF glow discharge in argon. Analyte signals are mainly extracted from the afterglow regime...... be used to study the distribution of a tantalum fluoride layer within the anodized tantala layer. Further, comparison is made with data obtained using glow-discharge optical emission spectroscopy, where elemental fluorine can only be detected using a neon plasma. The ionization mechanisms responsible...... for the formation of negative ions in glow discharge time-of-flight mass spectrometry are briefly discussed....

  11. Effects of microstructure on the elastic properties of selected Ta2O5--Eu2O3 compositions

    International Nuclear Information System (INIS)

    Malarkey, C.J.

    1977-06-01

    Elastic properties and internal friction of selected compositions of tantala-doped monoclinic europia were studied at temperatures up to 1500 0 C using the sonic resonance technique. Unit cell parameters between 25C and 1000 0 C for monoclinic Eu 2 O 3 were calculated from high temperature x-ray diffractometer data. Large-grained monoclinic specimens having less than 6.0 Ta cation percent substitution exhibited anomalous elastic behavior when thermally cycled. Compositions above this addition level exhibited linear elastic behavior. Internal friction values also varied abnormally with grain size, composition, and temperature. The anomalous behavior was attributed to microcracking caused by thermal expansion anisotropies. The critical grain size was found to be approximately 14 μm. The high temperature diffractometry measurements supported the postulate that the grain coarsening effect associated with sintered monoclinic Eu 2 O 3 is the controlling factor for microcracking

  12. Structural and optical properties of sol-gel deposited proton conducting Ta{sub 2}O{sub 5} films

    Energy Technology Data Exchange (ETDEWEB)

    Ozer, N.; Lampert, C.M.

    1995-08-01

    Proton conducting tantalum oxide films were deposited by spin coating using a sol-gel process. The coating solutions were prepared using Ta(OC{sub 2}H{sub 5}){sub 5} as a precursor. X-ray diffraction studies determined that the sol-gel films, heat treated at temperatures below 400 C, were amorphous. Films heat treated at higher temperatures were crystalline Ta{sub 2}O{sub 5}. The solar transmission values (T{sub s}) of tantala films on glass generally range from 0.8--0.9 depending on thickness. The refractive index and the extinction coefficient were evaluated from transmittance characteristics in the UV-VIS-NIR regions. The refractive index values calculated at 550 nm increased from 1.78 to 1.97 with increasing heat treatment from 150 to 450 C. The films heat treated at different temperatures showed low absorption with extinction coefficients of less than k=1x10{sup -3} in the visible range. Spectrophotometric and impedance spectroscopic investigations performed on Ta{sub 2}O{sub 5} films revealed that these films have protonic conductivity of 3.2x10{sup -6} S/cm. The films are suitable for proton conducting layers in electrochromic (EC) devices.

  13. Medium-Index Mixed-Oxide Layers for Use in AR-Coatings

    Science.gov (United States)

    Ganner, Peter

    1986-10-01

    Ttedesign philosophy of MC-AR-Coatings can be divided into two categories: a) Restriction to two film materials, namely one high-index and one low-index material and b) Use of medium-index layers in addition to high- and low-index layers. Both philosophies have advan-tages and drawbacks. In case a) the total number of layers necessary to obtain a required reflectance curve has to be higher. Thus in case of production errors it can be a problem to find out which layer was responsible for a deviation of the measured reflectance from the nominal one. In case b) using more than two materials reduces the total number of layers and consequently, pinpointing the cause of even small production errors is made simpler. Unfortunately there are not many materials commercially available which can be used to make hard, durable and robust films in the medium-index range namely between n=1.65 and n=2.00. In this paper the results of homogeneous mixtures of Alumina (Al203) and Tantala (Ta205) used for EB-gun evaporated medium-index films in AR-coatings is presented. It is shown that by proper adjustment of the weight percentages of the oxide mixture one can get homogeneous films in this index range. A number of design examples show the favourable application of such layers in AR-coatings. Among the most important ones is the well known QHQ-design for BBAR-coatings as well as AR-designs of the multiple half wave type with extended bandwidth. Further applications of the mixed-oxide layers are AR-coatings for cemented optical elements and beam splitters.

  14. The Effects of Beta Rays (Tritium) on the Growth of Rickettsiae and Influenza Virus; Effets du Rayonnement Beta (du Tritium) sur la Proliferation des Rickettsies et des Virus de la Grippe; 0414 0435 ; Influencia de los Rayos Beta (Tritio) sobre la Multiplicacion de Rickettsia y de Virus de la Gripe

    Energy Technology Data Exchange (ETDEWEB)

    Greiff, D. [Marquette University, School of Medicine, Milwaukee, WI (United States)

    1962-02-15

    infljujency iz: otnosjashhihsja k horionu allantoidnyh plenok zarodyshevyh jaic nabljudalos' posle in{sup e}kcii okisi tritija do zarazhenija virusom. Cherez dva chasa posle ino- kuljacii agenta infekcii bylo obnaruzheno tysjachekratnoe, uvelichenie virusa v otnosjashhihsja k horionu allantoidnyh zhidkostjah obrabotannyh jaic. Kogda, cherez vosem' chasov posle infekcii v otnosjashhihsja k horionu allantoidnyh zhidkostjah kontrol'nyh jaic okazalos' znachitel'noe kolichestvo virusa, ID{sub 50} obrabotannyh tritiem jaic sostavljal 10{sup -5,6}; obe serii imeli ID{sub 50} v razmere 10{sup -7.5} cherez 24 chasa posle infekcii. Kolichestvo virusa v plenkah, obrabotannyh tritiem jaic takzhe vozroslo. Jetot virus byl osvobozhden pri pomoshhi udalenija i promyvanija plenok, ih sushki posredstvom sublimacii v vakuume pri nizkih temperaturah i s pomoshh'ju proryva kletok plenok putem regidracii s destillirovannoj vodoj. (author)

  15. The Co{sup 60} Irradiation Facility and the Gamma Field at Riso; Appareil d'irradiation au cobalt-60 et champ sous irradiation gamma, a Riso; Ustanovka dlya obluchenij, rabotayushchaya na So60, i pole gamma-luchej v rizo; Instalacion de irradiacion con cobalto-60 y campo de irradiacion gamma en el centro de Riso

    Energy Technology Data Exchange (ETDEWEB)

    Brynjolfsson, A; Holm, N W [Danish Atomic Energy Commission, Establishment Riso (Denmark)

    1960-07-15

    . En la memoria se facilitan detalles relativos a su construccion y a las normas de seguridad que se han observado en el proyecto. Las determinaciones dosimetricas se han efectuado con ayuda de cuatro tipos de aparatos diferentes: 1. Camaras de ionizacion 2. Calorimetros 3. Dosimetros de Fricke 4. Peliculas fotograficas. En la memoria se hace asimismo una descripcion general del campo de irradiacion gamma y se dan detalles referentes a la posicion de la fuente. La intensidad de irradiacion es de unos 100 roentgens/hora a una distancia de 1 m. Las plantas sometidas a la irradiacion se cultivan en un campo de 15 m de radio. Se indican brevemente los diferentes productos que se han sometido a irradiacion en las dos instalaciones. (author) [Russian] V doklade opisyvayutsya ustanovka dlya obluchenij na Co{sup 60} i pole gammaluchej v Otdelenii sel'skogo khozyajstva Nauchno-issledovatel'skogo tsentra v Rizo. Ustanovka dlya obluchenij na Co{sup 60} soderzhit 1800 kyuri Co{sup 60}. Dayutsya detali konstruktsii, a takzhe ukazyvayutsya mery bezopasnosti, kotorye uchteny v konstruktsii ustanovki. Dozimetriya proizvoditsya pri pomoshchi chetyrekh razlichnykh metodov: 1. Ionizatsionnykh kamer; 2. Kalorimetrii 3. Dozimetra Frikke 4. Fotograficheskikh plenok Daetsya obshchee opisanie polya gamma-izluchenij, vklyuchaya detali raspolozheniya istochnikov. Norma dozirovaniya - priblizitel'no 100r/ch na rasstoyanii v odin metr. Dlya vyrashchivaniya obluchaemykh rastenij beretsya pole s radiusom v 15 metrov. Daetsya kratkoe ukazanie kategorii produktov, podvergaemykh oblucheniyu v dvukh ustanovkakh. (author)

  16. The use of radioactive tracers in lubrication and wear research; Emploi des indicateurs radioactifs dans les recherches sur la lubrification et l'usure; Ispol'zovanie mechenykh atomov pri issledovanii voprosov smazki i iznosa; Utilizacion de los indicadores radiactivos en los estudios sobre la lubricacion y el desgaste

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, R B; Grunberg, L; Milne, A A; Wright, K H.R. [Lubrication, Wear and Mechanical Engineering Aspects of Corrosion Division, National Engineering Laboratory, Thorntonhall, Glasgow (United Kingdom)

    1962-01-15

    chastitsy okisi zheleza ispol'zuyutsya dlya izucheniya ikh roli v protsesse iznosa. Reaktivnost' poverkh- nosti zakalennykh metallov izuchalas' s pomoshch'yu mechennoj uglerodom-14 stearinovoj kisloty i rastvora sery-35. Skorost' reaktsii v primesi masla dlya shesteren analizirovalas' putem propuskaniya korotkikh impul'sov ehlektrotoka po metallicheskim provodam, opushchennym v rastvory soedinenij, mechennykh seroj-35 i fosforom-32. Sozdanie stojkikh k istiraniyu plenok na poverkhnosti zub'ev shesterenok izuchalos' kak funktsiya nagruzki, skorosti i vremeni raboty. Vopros, vstrechayushchijsya vo mnogikh iz vidov ehtogo primeneniya, sostoit v prevrashchenii izmeryaemoj aktivnosti v absolyutnye kolichestva materialov, prisutstvuyushchikh na poverkhnosti plenok ili v produktakh iznosa. Dlya ehtoj zhe tseli ispol'zovalis' metody kalibrovaniya. (author)

  17. Use of Synthetic Polymers in Nuclear Emulsions for Fast-Neutron Dosimetry; Primenenie sinteticheskikh polimerov v yadernykh ehmul'siyakh dlya dozimetrii bystrykh nejtronov

    Energy Technology Data Exchange (ETDEWEB)

    Bradna, F. [Laboratorija Radiologicheskoj Dozimetrii Instituta Jadernykh Issledovanij CHSAN Praga, CSSR (Czech Republic)

    1967-01-15

    -acetate substrate 190-{mu}m thick, which was an effective proton radiator. The emulsions were irradiated with fast neutrons of fluence 1.56 x 10{sup 8} n/cm{sup 2} from an RaD-Be source. For increased efficiency of neutron detection, supplementary proton radiators such as polyvinyl alcohol (PVA), tri-acetate (T) and polyethylene (PE) of the optimum thickness were used during irradiation of the emulsion. Dosimetric analysis of the results gave the following: (1) The efficiency of detection was increased, in comparison with normal gelatin emulsions, by: (a) up to 25% when using polymers No. 1 and No. 2, depending on the degree of filling, and (b) 100% when polymer No. 1 was used in a hydrogen-saturated emulsion taken as a standard polymer-gelatin emulsion (SPGE), (2) When the optimum supplementary proton radiators (PVA, T, PE) were added to this SPGE, its detection efficiency was further increased to 330%. (author) [Russian] V dannoj rabote predlagajutsja rezul'taty ispytanij svojstv v Laboratorii radiologicheskoj dozimetrii IJaI ChSAN vodorodom obogashhennyh jadernyh jemul'sij, prednaznachennyh dlja registracii bystryh nejtronov i privoditsja sravnenie dozimetricheskih harakteristik jetih jemul'sij novogo tipa s harakteristikami do sih por ispol'zuemyh zhelatinovyh jemul'sij. Iz serii v laboratorii sintezirovannyh polimerov naibolee interesnymi okazalis': 1) olivinil'acetal' 2,4-disul'fokisloty benzaldegida (polimer N2 1); 2) sopolimer a-acetilaminoakrilovoj kisloty i N-vinilpirrolidona (polimer No 2). Otdel'no izuchalas' vozmozhnost' primenenija rastvorov polivinilovogo spirta s bolee vysokim soderzhaniem vodoroda po sravneniju s vysheukazannymi ispytannymi polimerami (No 1, No 2) dlja propityvanija polimero-zhelatinovyh jemul'sij i dlja prigotovlenija iz nego plenok v kachestve radiatora protonov. Polimery N21 i N9 2 primenjalis' predvaritel'no v ispytatel'noj ammiachnoj jemul'sii. Bylo ustanovleno, chto polimer No 1 ne okazyvaet zametnogo vlijanija na fotohimicheskie svojstva

  18. Lattice Dynamics of Transition Metals; Dynamique de Reseau des Metaux de Transition

    Energy Technology Data Exchange (ETDEWEB)

    Woods, A. D.B. [Chalk River Nuclear Laboratories, Chalk River, ON (Canada)

    1965-04-15

    {sup 12} c/s para {zeta} = 1.0. Si estas y otras particularidades observadas son anomalias de Kohn, sus posiciones son compatibles con las dimensiones de la superficie de Fermi propuesta por Lomer para los metales de la columna V. Se formula la hipotesis de que las sorprendentes diferencias existentes entre la relacion de dispersion del niobio y la del molibdeno (metales que, segun se cree, poseen estructuras de banda muy semejantes) reflejan diferencias en las energias de Fermi y, por tanto, en las superficies de Fermi de estos materiales. (author) [Russian] Dispersionnoe sootnoshenie chastota/volnovoj vektor v(q) dlja obychnyh vidov kolebanij nekotoryh ob{sup e}mno-centrirovannyh kubicheskih kristallov perehodnyh metallov bylo nedavno izmereno pri komnatnoj temperature. Krivye dispersii dlja niobija, izmerennye Nakagovoj i Vudsom, projavili nekotorye ochen' neobychnye cherty, i rezul'taty mozhno bylo privesti v sootvetstvie tol'ko s pomoshh'ju modeli Born fon Karmana, esli vkljuchit' vzaimodejstvija s ochen' otdalennymi chlenami rjada dal'she vos'mogo. Posledujushhie izmerenija Vudsom tantala dali ochen' pohozhie rezul'taty. Jeto ne udivitel'no, poskol'ku niobij i tantal nahodjatsja v V gruppe periodicheskoj tablicy i mnogie iz ih jelektronnyh svojstv odinakovy. Izmerenija krivyh dispersij molibdena Vudsom i Chenom i vol'frama Chenom i Brok- hauzom pokazali, chto, hotja u jetih metallov, kotorye nahodjatsja v gruppe VI periodicheskoj tablicy, dispersionnye sootnoshenija javljajutsja analogichnymi, jeti dispersionnye sootnoshenija sil'no otlichajutsja ot dispersionnyh sootnoshenij dlja niobija i tantala, nahodjashhihsja v gruppe V. Osnovnye cherty u(q) dlja molibdena i vol'frama ochen' blizko opisyvajutsja tret'im chlenom rjada simmetrichnoj po osjam silovoj modeli Born-fon Karmana, hotja nekotorye vazhnye cherty ne vosproizvodjatsja jetoj model'ju. Odnoj iz takih chert javljaetsja razitel'naja anomalija v prodol'noj [{zeta}{zeta}{zeta}] vetvi (L) dlja molibdena, gde

  19. High-Dose Ionizing Radiation Photographic Dosimetry; Mesure, par des Methodes Photogra Phiques, de Doses Elevees de Rayonnements Ionisants; 0424 041e 0422 041e 0413 0420 0414 ; Dosimetria Fotografica de Dosis Elevadas de Radiaciones Ionizantes

    Energy Technology Data Exchange (ETDEWEB)

    Trousil, J.; Bucina, I. [Institute for Research Production and Application of Radioisotopes Prague, Czechoslovakia (Czech Republic)

    1965-06-15

    sobre las emulsiones rapidas y lentas con elevada concentracion de plata. En las emulsiones que se usan para la medicion de dosis elevadas y que se revelan en presencia de retardadores, se ha determinado la influencia ejercida por la energia y la atenuacion de la imagen latente sobre la precision de las determinaciones. Por ultimo, se describen los errores de la evaluacion fotografica de dosis elevadas hallados aplicando metodos estadisticos al analisis de los resultados experimentales. Se examina tambien el incremento del error en las regiones de debil y fuerte ennegrecimiento. Tambien se consideran los errores debidos a la calibracion de los aparatos, la influencia de la energia, la atenuacion de la imagen latente, el tratamiento quimico y la medicion del ennegrecimiento. La hipotesis de que la dosis medida con dosimetros de pelicula corresponde a la dosis recibida por el organismo entero, constituye un error que no se toma en consideracion. (author) [Russian] V jetoj rabote opisyvaetsja fotograficheskaja dozimetrija ionizirujushhej radiacii v diapazone ot 10 millirad do 1000 rad (dlja gamma-izluchenija bolee vysokoj intensivnosti). Pri jetom metode ispol'zujutsja dve fotoplenki s razlichnoj jemul'siej, kotorye odnovremenno pomeshhajut v odin i tot zhe plenochnyj dozimetr. Sushhestvennoj chertoj jetogo metoda javljaetsja to, chto dozy v vysheprivedennom diapazone mogut byt' opredeleny bez znanija o tom, chto imelo mesto obluchenie bol'shimi dozami, s tochnost'ju luchshej chem {+-}25%v predelah vsego diapazona doz (doveritel'nyj interval 95%), a takzhe to, chto jenergiju obluchenija v plenke mozhno opredelit' s horoshej approksimaciej. Rassmatrivajutsja pribory, vidy plenok i himicheskaja obrabotka, kotorye pozvoljajut proizvodit' jeti izmerenija. Opisyvaetsja princip izgotovlenija densitometra, s pomoshh'ju kotorogo mozhno izmerit' potemnenie fotoplenki s odinakovoj tochnost'ju v diapazone ot D = 0 do D = 6. Takim putem mozhno ispol'zovat' vsju oblast' imejushhegosja

  20. Research Applications of Beta-Particle Techniques: Back-Scattering and X-Ray Excitation; Applications de l'irradiation beta dans la recherche: retrodiffusion et excitation de rayons X; Primenenie metodov beta-chastits v issledovatel'skoj rabote: obratnoe rasseyanie i vozbuzhdenie rentgenovskikh luchej; Aplicacion de la irradiacion beta en la investigacion: retrodispersion y excitacion de rayos X

    Energy Technology Data Exchange (ETDEWEB)

    Mueller, R H [Los Alamos Scientific Laboratory, University of California, Los Alamos, NM (United States)

    1962-01-15

    tecnicas confirman la opinion de que los radioisotopos encierran enormes promesas en el terreno cientifico y tecnico. Por lo que se refiere a las fuentes de rayos X, puede decirse que todo cuanto se realiza en el terreno de la tecnologia de los rayos X, salvo la determinacion de la estructura de los cristales, puede hacerse con mayor sencillez recurriendo a los medios citados. Es mas, si se emplearan fuentes de muchos curies, puede que incluso llegue a ser posible efectuar esas determinaciones. (author) [Russian] Prozvedennye v ehtoj laboratorii za poslednie sem', let issledovaniya ustanovili tochnye usloviya obratnogo rasseyaniya beta-chastits, i ehti metody byli dopolneny metodami ispol'zovaniya vozbuzhdennykh izotopami rentgenovskikh luchej. Vozbuzhdennye takim sposobom rentgenovskie luchi privlekli .shirokoe vnimanie vo vsem svete i vo mnogikh sluchayakh oni revolyutsionizirovali metody promyshlennoj kalibrovki. V nastoyashchem doklade razbirayutsya primeneniya k tochnoj abzorbtsiometrii, izmereniyu tolshchiny plenok, opoznovaniyu i kolichestvennomu opredeleniyu veshchestv putem izmereniya absorbtsii po krayam, a takzhe k bumazhnoj khromatografii. V poslednem sluchae, khromato grammy mogut izuchat'sya posredstvom beta-absorbtsii, absorbtsii rentgenovskimi luchami ili vozbuzhdeniem rentgenovskikh luchej v razlichnykh zonakh bombardirovkoj beta-luchami. Sravnivayutsya i otsenivayutsya ehti razlichnye podkhody. Byl izuchen tselyj ryad mikrokhimicheskikh metodov i libo posredstvom beta-absorbtsii, libo posredstvom vozbuzhdeniya rentgenovskikh luchej beta-chastitsami mogut byt' opoznany i opredeleny nebol'shie kolichestva veshchestv. Nizshie predely detektsii ne tak:maly, kak ehto dostizhimo metodom radioaktivnykh indikatorov, no imeetsya ryad drugikh preimushchestv, glavnoe iz kotorykh zaklyuchaetsya v tom, chto operatsii proizvodyatsya s zadelannymi istochnikami, chto pochti sovershenno isklyuchaet vozmozhnost' radioaktivnogo zarazheniya. Na osnovanii ehtikh dannykh byli

  1. Graft Polymerization of Styrene to Polyethylene; Polymerisation par greffage du styrene sur des pellicules de polyethylene; Privitaya polimerizatsiya stirola k poliehtilen; Polimerizacion por injerto de estireno en polietileno

    Energy Technology Data Exchange (ETDEWEB)

    Silverman, J.; Srinivasan, S. I.; Phalangas, C. J. [Department of Chemical Engineering, University of Maryland, College Park, MD (United States)

    1963-11-15

    peliculas y borra d e polietileno para dosis de exposicion a rayos gamma de {sup 60}Co hasta 8,0 x 10{sup 5} r/h. Determinaron tambien la velocidad de transformacion del estireno en su homopoirmero, en las suspensiones de borra. Examinaron al microscopio las peliculas injertadas a fin de evaluar la proporcion de homopolfmero ocluido. Los resultados obtenidos indican que la mayor parte del incremento de peso en las muestras de pelicula corresponde al homopolfmero ocluido. En las pruebas con borra, en las cuales el incremento de peso se debe principalmente al copolimero injertado, dicho incremento es aproximadamente proporcional a la dosis y la velocidad de reaccion es casi proporcional a la rafe cuadrada de la intensidad de la dosis gamma. La reducida energia de activacion correspondiente a la velocidad de reaccion excluye la posibilidad de controlar la difusion en la borra y en las peliculas delgadas para intensidades de exposicion inferiores a 10{sup 5} r/h. En los experimentos con borra a 18{sup o}C e intensidades de 7,2 x 10{sup 4} r/h, la velocidad de formacion del homopolfmero coincide con el valor ya conocido para la polimerizacion del estireno puro. La energia de activacion, a saber, 3,5 kcal/mol, representa practicamente la mitad de la indicada para el monomero puro. (author) [Russian] Izuchenie opublikovannykh dannykh ob initsiirovannoj oblucheniem privitoj polimerizatsii stirola k plenkam poliehtilena nizkoj plotnosti pokazyvaet, tfgo skorost' prirosta vesa lish' neznachitel'no zavisit ot moshchnosti gamma-oblucheniya i tolshchiny plenki. Pokazano, chto modeli, primenyavshiesya ranee issledovatelyami dlya ob{sup y}asneniya dannykh prirosta vesa dlya otsenki konstant skorosti, ne godyatsya. Privedeny ehksperimental'nye dannye po privivaniyu pri temperaturakh 18{sup o}C i 40{sup o}C s ispol'zovaniem poliehtilenovykh plenok, legkoj melkokristallicheskoj kal'tsinirovannoj sody i istochnika Co{sup 60} s gamma-izlucheniem moshchnost'yu do 8,0 x 10{sup 5} r/ch. Izmerena

  2. Radioisotopes in the physical chemistry of corrosion processes and their inhibition; Les radioisotopes dans la chimie physique des processus de corrosion et de leur inhibition; Primenenie radioizotopov v fizicheskoj khimii protsessov korrozii i ikh tormozheniya; Los radioisotopos en la quimica fisica de los procesos de corrosion y de inhibicion

    Energy Technology Data Exchange (ETDEWEB)

    Cartledge, G H [Chemistry Division, Oak Ridge National Laboratory, Oak Ridge, TN (United States)

    1962-03-15

    periodico, es particularmente adecuado para algunos de estos estudios. Las ventajas do este elemento estriban, en sus propiedades nucleares. La memoria resume las propiedades quimicas de los compuestos de tecnecio y las compara con las de los compuestos correspondientes de {sup 51}Cr, de molibdeno y de wolframio, que con tanta frecuencia se emplean en el estudio de la inhibicion. La memoria describe seguidamente ciertos estudios experimentales como ejemplo de los usos a que se ha destinado el tecnecio en los trabajos de este tipo. Entre ellos menciona estudios empiricos de su accion como eficaz inhibidor de la corrosion del hierro, y observaciones de la actividad de superficie realizadas durante periodos largos de tiempo. Otros estudios efectuados con {sup 99}Tc y con {sup 131}I han demostrado la importancia de la adsorcion competitiva de iones en la determinacion de la cinetica de los procesos de corrosion y de inhibicion. Como tercer ejemplo, describe como las propiedades excepcionales del tecnecio han permitido distinguir claramente las contribuciones relativas del oxigeno de las del inhibidor oxidante en el mantenimiento de la pasividad. (author) [Russian] Sredi faktorov, vkhodyashchikh v fundamental'noe izuchenie ehlektrokhimicheskikh protsessov korrozii i tormozheniya, vydelyayutsya v chastnosti sleduyushchie: a) razlichnye vidy adsorbtsionnykh yavlenij; b) ionoobmennye svojstva passivnykh plenok; c) ehlektrokhimicheskaya kinetika kak anodnykh, tak i katodnykh protsessov, proiskhodyashchikh mezhdu metallom i korrozijnoj sredoj. Teper' pri pomoshchi radioizotopov mozhno provesti nekotorye issledovaniya ehtikh yavlyaenij, kotorye nevozmozhno osushchestvit' obychnymi sredstvami. Tekhnetsij, gomolog margantsa v periodicheskoj sisteme, okazalsya ves'ma podkhodyashchim dlya nekotorykh ehtikh issledovanij. Ego yadernye svojstva krajne interesny u ehtom otnoshenii. V doklade kratko izlagayutsya khimicheskie svojstva soedinenij tekhnetsiya, protivopostavlennye svojstvam

  3. Chemical Behaviour of C{sup 11} in Liquid Hydrocarbons; Comportement Chimique de {sup 11}C dans les Hydrocarbures Liquides; Khimicheskaya kharakteristika ugleroda-11 v zhidkikh uglevodorodakh; Comportamiento Quimico del {sup 11}C en Hidrocarburos Liquidos

    Energy Technology Data Exchange (ETDEWEB)

    Voigt, A. F.; Clark, D. E.; Mesich, F. G. [Institute of Atomic Research and Department of Chemistry, Iowa State University, Ames, IA (United States)

    1965-04-15

    moleculas blanco en distintas condiciones de dosificacion. Los experimentos en curso sobre moleculas analogas en tamano a las del blanco han contribuido a la aclaracion de los mecanismos de recombinacion de los atomos de retroceso. Particular interes reviste el rendimiento de productos con un atomo de carbono mas que el blanco, que resultan de una reaccion de adicion. La localizacion del atomo adicional en una molecula blanco que tenga varios lugares de adicion proporciona informacion sobre la naturaleza del proceso. Cuando el atomo de retroceso es moderado y su energia disminuye hasta el punto en que es posible la formacion de un enlace, al menos temporal, el exceso de energia que el atomo llC cede al sistema puede originar la ruptura de otros enlaces del complejo activado, lo que suele dar origen a un producto de dos atomos de carbono. Si el complejo es capaz de conservar su integridad, suele resultar un producto de adicion. Por tanto, la comparacion del rendimiento de compuestos de dos atomos de carbono (acetileno, etileno y etano) y de productos de adicion proporciona una informacion valiosa sobre la energia a la que pueden formarse enlaces estables, y sobre la naturaleza del grupo que contiene el {sup 11}C y que participa en la reaccion. (author) [Russian] Uglerod-11 obrazuetsja v rezul'tate reakcii C{sup 12}({gamma}, n)C{sup 11} v puchke tormoznogo izluchenija v sinhrotrone s jenergiej jelektronov 70 Mjev. V kachestve veshhestva misheni primenjalis' zhidkie uglevodorody s pjat'ju i shest'ju atomami ugleroda, v tom chisle normal'nye razvetvlennye i aliciklicheskie pentany i geksany, a takzhe benzol. Povedenie C{sub 11} izuchalos' metodom gazohromatograficheskogo razdelenija produktov, scheta aktivnosti C{sub 11} v gazovom potoke v kamere, pomeshhennoj v scintilljacionnyj schetchik kanal'nogo tipa. V kazhdom jeksperimente vyhody razlichnyh produktov sravnivalis' s vyhodom acetilena kak vnutrennego standarta, a takzhe libo s pokazanijami registratora tantala, libo s

  4. Design and Function of a Brain Scanner for Clinical Use; Etude d'un Appareil de Scintigraphy du Cerveau - Son Role Clinique; Ustrojstvo i funktsiya pribora dlya skennirovaniya mozga i ego klinicheskoe ispol'zovanie; Diseffo y Funcion de un Aparato de Exploracion del Cerebro para Uso Clinico

    Energy Technology Data Exchange (ETDEWEB)

    Paul, W.; Morley, T. P. [Department of Pathological Chemistry and Department of Surgery, University Of Toronto (Canada)

    1964-10-15

    predstavljajutsja v vide asimetrogammagramm i razdel'nyh levogo i pravogo fotograficheskih dvuhrazmernyh izobrazhenij. Impul'sy ot kazhdogo detektora podajutsja na kontur usilitel'-diskriminator i zatem na differencial'nyj kontur, kotoryj pechataet levuju ili pravuju otmetki s cel'ju pokaza preobladanija koncentracii radioaktivnosti sleva ili sprava. Impul'sy ot kazhdogo kontura usiljtel'-diskriminator podajutsja takzhe na pereschetnye ustrojstva, kotorye v svoju ochered' vozbuzhdajut lampy, ustanovlennye v svetonepronicaemom pomeshhenii. Dve lampy, intensivnost' sveta kotooyh poedstavljaet soboj Funkciju aktivnosti, izmerennoj sootvetstvujushhimi detektorami, montirujutsja na obshhej podstavke, peredvigaemoj s pomoshh'ju dvigatelej Sel'sina v sisteme detektora sinhronno s generatorami Sel'sina, tem samym davaja vozmozhnost' primenjat' ustanovlennuju na rasstojanii registrirujushhuju ustanovku. Cilindricheskie linzy fokusirujut lampovye istochniki na plenku, pri jetom registracija kak sprava, tak i sleva osushhestvljaetsja odnovremenno na rentgenovskoj plenke razmerom 28 ch 36 sm. Hotja operator mozhet ustanovit' sootvetstvujushhuju predvaritel'no opredelennuju velichinu srednej sily toka lampy v shirokom diapazone skorosti scheta, operatoru predostavljaetsja bol'shaja svoboda v svjazi s nalichiem v kassete treh plenok, kazhdaja iz kotoryh obespechivaet optimal'nuju kontrastnost' v razlichnom diapazone skorosti scheta. Pacientam vvodilis' 350 mkjuri joda-131 s syvorotochnym al'buminom cheloveka posle predvaritel'noj obrabotki rastvorom Ljugolja. Skennirovanie osushhestvljalos' cherez 24 - 72 chasa. Obychno bylo dostatochno poluchenija odnoj skennogrammy. U nekotoryh pacientov skennogrammy snimalis' povtorno v peredne-zadnem napravlenii. V period s sentjabrja 1961 goda po nojabr' 1962 goda u 653 pacientov bylo snjato 789sken- nogramm. U 109 pacientov iz jetogo chisla diagnoz podtverdilsja, u 88 pacientov byli obnaruzheny opuholi. Byla ustanovlena lokalizacija 23 iz 30 glioblastom i